The role of sulfate transporters in virulence of Xanthomonas oryzae pv. oryzicola
A. READ (1), A. Bogdanove (2) (1) Plant Pathology and Plant Microbe Biology - School of Integrative Plant Science - Cornell University, U.S.A.; (2) Plant Pathology and Plant-Microbe Biology - School of Integrative Plant Science - Cornell University, U.S.A.

Xanthomonas oryzae pv. oryzicola (Xoc) causes bacterial leaf streak of rice (BLS), a disease with no known R gene resistance. Xoc strain BLS256 encodes 28 type III secreted transcription activator-like effectors (TALEs), which modulate host gene expression. The BLS256 TAL effector Tal2g targets the susceptibility (S) gene OsSULTR3;6, a predicted sulfate transporter gene. Disruption of tal2g leads to decreased lesion length and fewer bacteria on the leaf surface. These deficiencies can be rescued by expression of designer TALEs targeting OsSULTR3;6, confirming its role as an S gene. OsSULTR3;6 is part of a 14 member gene family in rice, 12 of which are predicted sulfate transporters. The full-length OsSULTR3;6 cDNA has been cloned as an mCherry fusion in order to determine subcellular localization and to aid in functional characterization. To assess whether an alternative sulfate transporter could act as a substitute S gene, designer TALEs were created targeting 11 predicted sulfate transporters and transformed into the tal2g mutant of BLS256. Target gene expression was measured by qRT-PCR and lesion length expansion monitored. No tested gene substitutes for OsSULTR3;6. In fact, activation of OsSULTR3;2 in the tal2g mutant leads to a further decrease in virulence. These data, along with the observation that tal2g is conserved across 11 examined Xoc strains may indicate a pressure to specifically activate OsSULTR3;6, making this an attractive target for engineered resistance.

Abstract Number: P9-297
Session Type: Poster